Decomposition in space

[Tigers!]

Prompted by watching Rogue One.

Once my daughter asked me is bodies would decompose in space. She was in year 8 at the time and had been studying decomposition.
We concluded that in space with a near perfect vacuum and lack of scavengers, microbes, water, sun etc. that bodies would not decompose.

Is that plausible?

 

[spikepipsqueak]

Not an expert, but we have a lot of anaerobic bacteria internally. It would be a race between the vacuum dessicating the surface and internal decomposition.

 

[T.G.G. Moogly]

They will not decompose biologically but they will decompose.

 

[BH]

The radiation would decompose the body somewhat. Most of the inner bacteria would die off or become inactive due to the cold I would think.

 

[barbos]

Assuming no sunlight you will turn into frozen chunk of meat which will stay that way for very long time.

 

[Loren Pechtel]

The environment isn't sterile--the body has it's own bacteria in it that would eventually destroy it even with no outside elements to speed the process up.

However, you won't see anything resembling Earth-style decomposition for a different reason: space is a vacuum. A body in space will soon be freeze-dried. (While the process is called freeze-drying that is because you normally freeze it first to prevent it from spoiling while doing the drying part, and to slow the process down so it happens more evenly. If you don't freeze it first it actually dries faster.) Lacking moisture the bacteria won't be able to devour it.

The fast drying will tear the body up somewhat (outer layers drying and shrinking while the inner layers are still moist--you'll get splits) and over time the UV from the sun will completely tear it up. A body in space will in time be reduced to bones, I don't think they will break down. A body in a holed spacesuit will stay a mummy for a long time.

 

[fromderinside]

from UCSB science line: http://scienceline.ucsb.edu/getkey.php?key=1692

1. Unless there's a source of heat nearby, the body will be quickly frozen, and decomposition will take thousands or even millions of years.
2. If there's heat, but no spacesuit or spacecraft, the body will very quickly dry out, because water evaporates extremely quickly in the vacuum of space. This will almost completely stop biological processes, and the lack of air will prevent weathering and chemical degradation.
3. If the astronaut died while wearing their spacesuit and the body stays warm, then decomposing of tissue will be almost as fast as on earth. But bones will last almost indefinitely. Of course, if the body happens to fall in to a planet, it will be destroyed by the extreme heat of re-entry into the atmosphere, like a meteorite

 

[Cheerful Charlie]

Prompted by watching Rogue One.

Once my daughter asked me is bodies would decompose in space. She was in year 8 at the time and had been studying decomposition.
We concluded that in space with a near perfect vacuum and lack of scavengers, microbes, water, sun etc. that bodies would not decompose.

Is that plausible?

A body would freeze solid and then lose water to sublimation. All bacteria would die. Frozen and deprived of water. Such a body would be freeze dried husk that lasted for a piece of forever.

 

[Elixir]

Yabut - WATER BEARS!

"They can withstand temperature ranges from 1 K (−458 °F; −272 °C) (close to absolute zero) to about 420 K (300 °F; 150 °C), pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space. They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce."

 

[RavenSky]

from UCSB science line: http://scienceline.ucsb.edu/getkey.php?key=1692

1. Unless there's a source of heat nearby, the body will be quickly frozen, and decomposition will take thousands or even millions of years.
2. If there's heat, but no spacesuit or spacecraft, the body will very quickly dry out, because water evaporates extremely quickly in the vacuum of space. This will almost completely stop biological processes, and the lack of air will prevent weathering and chemical degradation.
3. If the astronaut died while wearing their spacesuit and the body stays warm, then decomposing of tissue will be almost as fast as on earth. But bones will last almost indefinitely. Of course, if the body happens to fall in to a planet, it will be destroyed by the extreme heat of re-entry into the atmosphere, like a meteorite

 

[Malintent]

Yabut - WATER BEARS!

"They can withstand temperature ranges from 1 K (−458 °F; −272 °C) (close to absolute zero) to about 420 K (300 °F; 150 °C), pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space. They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce."

They would be in hibernation in the space environment. so while present, and not "dead".. they would not be "alive" by any reasonable definition.

 

[bilby]

Yabut - WATER BEARS!

"They can withstand temperature ranges from 1 K (−458 °F; −272 °C) (close to absolute zero) to about 420 K (300 °F; 150 °C), pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space. They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce."

They would be in hibernation in the space environment. so while present, and not "dead".. they would not be "alive" by any reasonable definition.

It seems that there are no reasonable definitions of 'alive', except in the most obvious cases.